Heretofore, orthopedic seats have been devised for use in adapting conventional chairs and the like for use by people having spinal abnormalities. Exemplary of such are those seats shown in U.S. Pat. Nos. 1,891,747 and 4,362,334. In general these seats have been designed with two criteria principally in mind. Firstly, they have been designed so as to be easily carried and mounted to a conventional chair. Secondly, they have been designed to provide a support that conforms to the abnormal body condition or posture of the individual users so that support contact is provided over relatively large areas of the thighs, buttocks, and back of the user while seated upon conventionally contoured chairs or the like.
Some common abnormal spinal conditions are illustrated in FIGS. 5-7 of the drawings. Scoliosis is abnormally lateral curvature of the spine. A right scoliosis condition is illustrated in FIG. 5. A left scoliosis abnormality would, of course, curve in the opposite lateral direction. Where the spine is too straight, i.e. with the spine insufficiently curved in the lordotic direction, the condition is referred to as hypolordosis, which is illustrated in FIG. 6. Conversely, where excessive forward curvature is present, i.e. with the spine insufficiently curved in the kyphodic direction, as shown in FIG. 7, the condition is known as hyperlordosis. In these figures normal curvature is illustrated in broken lines while the actual shape of the individual with the abnormality is shown in solid lines.
Though reconfiguring conventional seats so as to provide direct body contact over a greater portion of the person is helpful, it would be of far greater benefit if the body itself were to be supported in a manner so as to reposition the spine from any abnormal orientation towards a normal orientation, or to maintain a normal orientation. It is to the provision of such an orthopedic seat that the present invention is therefore primarily directed.